CODEWITHSUNDEEP
javaunit-testingjunitmockito
César Castro Aroche
César Castro Aroche

Reputation: 775

Mockito thenReturn returning different values

So I have test like this:

public class TimesheetServiceTest {
    @Mock
    Repository repository;
    @Mock
    ServiceToMockResult serviceToMockResult;
    @InjectMocks
    private ServiceToTest serviceToTest = new ServiceToTestImpl();

    @Test
    public void testLongResult() {
        when(serviceToMockResult.getResult(any(String.class)))
                .thenReturn(20L); //it's supposed to always return 20L
        //8 items length result list
        List<Long> results = this.serviceToTest.getResults();
       //some more testing after ....
    }
}

As you can see the serviceToMock.getResult() method gets called inside of the ServiceToTest. So after doing this I get the 8 results I expect but some of them are value 0, and I also noticed that it's always position 5 and 7 in list. It's worth noticing that when I call serviceToMock.getResult() directly in test without passing through the other class, I get the expected result.

Expected Result

20, 20, 20, 20, 20, 20, 20, 20

Actual Result

20, 20, 20, 20, 20, 0, 20, 0

Upvotes: 0

Views: 158

Answers (2)

Lesiak
Lesiak

Reputation: 25946

Argument matcher any(String.class) matches any String, excluding nulls.

See ArgumentMatchers.any documentation:

public static <T> T any(Class<T> type)

Matches any object of given type, excluding nulls.

Most likely you are calling serviceToMockResult.getResult() with a null argument. As such a call is not stubbed, default value for the return type is returned (which is 0 for long)

Upvotes: 3

MD Ruhul Amin
MD Ruhul Amin

Reputation: 4502

While injecting mocks to a bean/service instead of creating it, let it create by mocks. Also init Mockito anntotation before processing.

Example:

public class TimesheetServiceTest {
    @Mock
    Repository repository;
    @Mock
    ServiceToMockResult serviceToMockResult;

    // let mockito create the service. 
    @InjectMocks
    private ServiceToTest serviceToTest;

    @Test
    public void testLongResult() {
        // Init mocks
        MockitoAnnotations.initMocks(this);

        when(serviceToMockResult.getResult(any(String.class)))
                .thenReturn(20L);
        // This should work fine.

    }
}

Upvotes: 0

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